Method and apparatus for multiplexing control information and data, and for transmitting the multiplexed control information and data in a mimo wireless communication system

ABSTRACT

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting uplink control information in a wireless communication system. A method for multiplexing uplink control information and uplink data and for transmitting the multiplexed uplink control information and uplink data according to one embodiment of the present invention comprises the following steps: encoding a first transmission block and a second transmission block to generate a first codeword and a second codeword; mapping the first codeword and the second codeword to one or more layers, respectively; and transmitting, via one or more antenna ports, each layer to which the first codeword and the second codeword are mapped, wherein the uplink control information is multiplexed only to either the first transmission block or to the second transmission block.

TECHNICAL FIELD

The following description relates to a wireless communication system andmore particularly to a method and apparatus for multiplexing andtransmitting control information and data in a MIMO wirelesscommunication system.

BACKGROUND ART

Multi-antenna transmission technology, which is also referred to asMulti-Input Multi-Output (MIMO) technology, can apply MIMO technologythat uses multiple transmit antennas and multiple receive antennas toimprove data transmission and reception efficiencies. MIMO technologymay include spatial multiplexing, transmit diversity, and beamforming. AMIMO channel matrix which is defined according to the number of receiveantennas and the number of transmit antennas may be decomposed into anumber of independent channels, each of which is referred to as a layeror stream. The number of layers or streams or the spatial multiplexingrate is referred to as a rank.

While the conventional 3GPP LTE system (for example, 3GPP LTE release 8or 9) supports uplink transmission through a single antenna, a 3GPPLTE-A system (for example, 3GPP LTE release 10), which is an evolutionof the 3GPP LTE standard, is under discussion to support uplinktransmission through up to 4 transmit antennas.

On the other hand, to efficiently perform downlink multi-antennatransmission, a feedback to a downlink channel may be transmitted from areceiving end (for example, a user equipment) to a transmitting end (forexample, a base station). Such feedback information may include a rankindicator (RI) and channel quality information (CQI) of a downlinkchannel. A Hybrid Automatic Repeat reQuest(HARQ)-Acknowledgement/Negative Acknowledgement (ACK/NACK) whichindicates whether or not decoding of downlink data is successful mayalso be transmitted from the downlink receiving end to the downlinktransmitting end. Information such as RI, CQI, and HARQ ACK/NACKinformation may be collectively referred to as uplink controlinformation (UCI).

UCI may be transmitted through a physical uplink control channel (PUCCH)or a physical uplink shared channel (PUSCH). When UCI is transmittedthrough a PUSCH, the UCI and uplink data may be multiplexed andtransmitted.

DISCLOSURE Technical Problem

Since the conventional system takes into consideration only single layertransmission when UCI is multiplexed and transmitted with uplink data,to support uplink multi-antenna transmission as described above, thereis a need to newly define a method for multiplexing uplink data and UCIfor multi-layer transmission.

An object of the present invention is to provide a method formultiplexing UCI and uplink data when one or more transport blocks (TBs)are transmitted in uplink.

Objects of the present invention are not limited to those describedabove and other objects will be clearly understood by a person havingordinary knowledge in the art from the following description.

Technical Solution

A method for multiplexing and transmitting uplink control informationwith uplink data in a wireless communication system according to anembodiment of the present invention in order to achieve the aboveobjects includes encoding a first transport block and a second transportblock to generate a first codeword and a second codeword, mapping eachof the first and second codewords to at least one layer, andtransmitting each of the at least one layer to which the first andsecond codewords are mapped through at least one antenna port, whereinthe uplink control information is multiplexed with one of the first andsecond transport blocks.

A transmitter for multiplexing and transmitting uplink controlinformation with uplink data in a wireless communication systemaccording to another embodiment of the present invention in order toachieve the above objects includes a transmission module fortransmitting an uplink signal to an uplink receiver, a reception modulefor receiving a downlink signal from the uplink receiver, and aprocessor for controlling the transmitter including the reception moduleand the transmission module, the processor being configured for encodinga first transport block and a second transport block to generate a firstcodeword and a second codeword, mapping each of the first and secondcodewords to at least one layer, and transmitting, using thetransmission module, each of the at least one layer to which the firstand second codewords are mapped through at least one antenna port,wherein the uplink control information is multiplexed with one of thefirst and second transport blocks.

The following features may be commonly applied to the above embodimentsof the present invention.

The transport block with which the uplink control information ismultiplexed may be a transport block which is assigned a higher MCSlevel from among the first and second transport blocks.

The transport block with which the uplink control information ismultiplexed may be a transport block having a lower modulation orderfrom among the first and second transport blocks.

The transport block with which the uplink control information ismultiplexed may be a transport block which is modulated according to aQuadrature Phase Shift Keying (QPSK) scheme from among the first andsecond transport blocks.

The uplink control information may be replicated in at least one layerto which a codeword to which the transport block with which the uplinkcontrol information is multiplexed is mapped is mapped.

The uplink control information may be spread in at least one layer towhich a codeword to which the transport block with which the uplinkcontrol information is multiplexed is mapped is mapped.

The uplink control information may include at least one of rankinformation, channel quality information, and Hybrid Automatic RepeatreQuest (HARQ)-Acknowledgement/Negative Acknowledgement (ACK/NACK)information.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

Advantageous Effects

According to the present invention, it is possible to provide a methodfor multiplexing UCI and uplink data when one or more transport blocks(TBs) are transmitted in uplink.

Advantages of the present invention are not limited to those describedabove and other advantages will be clearly understood by a person havingordinary knowledge in the art from the following description.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention, illustrate various embodiments of theinvention and together with the description serve to explain theprinciple of the invention. In the drawings:

FIG. 1 illustrates the structure of a radio frame used in a 3GPP LTEsystem.

FIG. 2 illustrates a resource grid in a downlink slot.

FIG. 3 illustrates the structure of a downlink subframe.

FIG. 4 illustrates the structure of an uplink subframe.

FIG. 5 illustrates a configuration of a general multi-antenna (MIMO)communication system.

FIG. 6 is a block diagram illustrating an uplink transmission structure.

FIG. 7 is a block diagram illustrating a procedure for processing atransport channel for an uplink shared channel (PUSCH).

FIG. 8 illustrates a method for mapping physical resources fortransmitting uplink data and Uplink Control Information (UCI).

FIG. 9 is a flowchart illustrating a method for multiplexing andtransmitting uplink control information and uplink data according to thepresent invention.

FIG. 10 illustrates a configuration of a transmission device accordingto the present invention.

BEST MODE

The embodiments described below are provided by combining components andfeatures of the present invention in specific forms. The components orfeatures of the present invention can be considered optional unlessexplicitly stated otherwise. The components or features may beimplemented without being combined with other components or features.The embodiments of the present invention may also be provided bycombining some of the components and/or features. The order of theoperations described below in the embodiments of the present inventionmay be changed. Some components or features of one embodiment may beincluded in another embodiment or may be replaced with correspondingcomponents or features of another embodiment.

The embodiments of the present invention have been described focusingmainly on the data communication relationship between a terminal and aBase Station (BS). The BS is a terminal node in a network which performscommunication directly with the terminal. Specific operations which havebeen described as being performed by the BS may also be performed by anupper node as needed.

That is, it will be apparent to those skilled in the art that the BS orany other network node may perform various operations for communicationwith terminals in a network including a number of network nodesincluding BSs. Here, the term “base station (BS)” may be replaced withanother term such as “fixed station”, “Node B”, “eNode B (eNB)”, or“access point”. The term “relay” may be replaced with another term“Relay Node (RN)” or “Relay Station (RS)”. The term “terminal” may alsobe replaced with another term such as “User Equipment (UE)”, “MobileStation (MS)”, “Mobile Subscriber Station (MSS)”, or “Subscriber Station(SS)”. The term “stationary terminal” may also be replaced with anotherterm such as “notebook” or “laptop”.

Specific terms used in the following description are provided for betterunderstanding of the present invention and can be replaced with otherterms without departing from the spirit of the present invention.

In some instances, known structures and devices are omitted or shown inblock diagram form, focusing on important features of the structures anddevices, so as not to obscure the concept of the present invention. Thesame reference numbers will be used throughout this specification torefer to the same or like parts.

The embodiments of the present invention can be supported by standarddocuments of at least one of the IEEE 802 system, the 3GPP system, the3GPP LTE system, the LTE-Advanced (LTE-A) system, and the 3GPP2 systemwhich are wireless access systems. That is, steps or portions that arenot described in the embodiments of the present invention for the sakeof clearly describing the spirit of the present invention can besupported by the standard documents. For all terms used in thisdisclosure, reference can be made to the standard documents.

Technologies described below can be used in various wireless accesssystems such as a Code Division Multiple Access (CDMA) system, aFrequency Division Multiple Access (FDMA) system, a Time DivisionMultiple Access (TDMA) system, an Orthogonal Frequency Division MultipleAccess (OFDMA) system, and a Single Carrier Frequency Division MultipleAccess (SC-FDMA) system. CDMA may be implemented with a radio technologysuch as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA maybe implemented with a radio technology such as Global System for Mobilecommunication (GSM), General Packet Radio Service (GPRS), or EnhancedData rates for GSM Evolution (EDGE). OFDMA may be implemented with aradio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE802.20, or Evolved-UTRA (E-UTRA). UTRA is a part of Universal MobileTelecommunication System (UMTS). 3rd Generation Partnership Project(3GPP) Long Term Evolution (LTE) is a part of Evolved-UMTS (E-UMTS) thatuses E-UTRA. 3GPP LTE employs OFDMA for downlink and employs SC-FDMA foruplink. LTE-Advanced (LTE-A) is an evolution of 3GPP LTE. WiMAX can beexplained by IEEE 802.16e standard (WirelessMAN-OFDMA Reference System)and advanced IEEE 802.16m standard (WirelessMAN-OFDMA advanced system).Although the present invention will be described below mainly withreference to 3GPP LTE and 3GPP LTE-A systems for the sake ofclarification, the technical spirit of the present invention is notlimited to the 3GPP LTE and LTE-A systems. For example, the technicalspirit of the present invention may also be applied to an OFDM basedmobile communication system (for example, an IEEE802.16m or 802.16xbased system) other than the LTE-A system.

FIG. 1 illustrates the structure of a radio frame used in the 3GPP LTEsystem. A radio frame includes 10 subframes and each subframe includes 2slots in the time domain. A unit time in which one subframe istransmitted is defined as a Transmission Time Interval (TTI). Forexample, one subframe may have a length of 1 ms and one slot may have alength of 0.5 ms. One slot may include a plurality of OFDM symbols inthe time domain. Because the 3GPP LTE system uses OFDMA in downlink, anOFDM symbol represents one symbol period. One symbol may be referred toas an SC-FDMA symbol or a symbol period in uplink. A Resource Block (RB)is a resource allocation unit which includes a plurality of consecutivesubcarriers in a slot. This radio frame structure is purely exemplary.Thus, the number of subframes included in a radio frame, the number ofslots included in a subframe, or the number of OFDM symbols included ina slot may vary in various ways.

FIG. 2 illustrates a resource grid in a downlink slot. Although onedownlink slot includes 7 OFDM symbols in the time domain and one RBincludes 12 subcarriers in the frequency domain in the example of FIG.3, the present invention is not limited to this example. For example,one slot may include 6 OFDM symbols when extended CPs are applied whileone slot includes 7 OFDM symbols when normal Cyclic Prefixes (CPs) areapplied. Each element on the resource grid is referred to as a resourceelement (RE). One resource block (RB) includes 12×7 resource elements.The number of RBs (NDL) included in one downlink slot is determinedbased on a downlink transmission bandwidth. The structure of the uplinkslot may be identical to the structure of the downlink slot.

FIG. 3 illustrates the structure of a downlink subframe. Up to the first3 OFDM symbols of a first slot within one subframe correspond to acontrol region to which a control channel is allocated. The remainingOFDM symbols correspond to a data region to which a Physical DownlinkShared Channel (PDSCH) is allocated. Downlink control channels used inthe 3GPP LTE system include, for example, a Physical Control FormatIndicator Channel (PCFICH), a Physical Downlink Control Channel (PDCCH),and a Physical Hybrid Automatic Repeat reQuest (HARQ) Indicator Channel(PHICH). The PCFICH is transmitted in the first OFDM symbol of asubframe and includes information regarding the number of OFDM symbolsused to transmit a control channel in the subframe. The PHICH includes aHARQ ACK/NACK signal as a response to uplink transmission. Controlinformation transmitted through the PDCCH is referred to as DownlinkControl Information (DCI). The DCI includes uplink or downlinkscheduling information or includes an uplink transmission power controlcommand for a UE group. The PDCCH may include a resource allocation andtransmission format of a Downlink Shared Channel (DL-SCH), resourceallocation information of an Uplink Shared Channel (UL-SCH), paginginformation of a Paging Channel (PCH), system information of the DL-SCH,information regarding resource allocation of a higher layer controlmessage such as a Random Access Response (RAR) that is transmitted inthe PDSCH, a set of transmission power control commands for individualUEs in a UE group, transmission power control information, andinformation regarding activation of Voice over IP (VoIP). A plurality ofPDCCHs may be transmitted within the control region. The UE may monitorthe plurality of PDCCHs. The PDCCHs are transmitted in an aggregation ofone or more consecutive Control Channel Elements (CCEs). Each CCE is alogical allocation unit that is used to provide the PDCCHs at a codingrate based on the state of a radio channel. The CCE corresponds to aplurality of resource element groups. The format of the PDCCH and thenumber of available bits are determined based on a correlation betweenthe number of CCEs and a coding rate provided by the CCEs. The basestation (eNB) determines the PDCCH format according to a DCI that istransmitted to the UE, and adds a Cyclic Redundancy Check (CRC) tocontrol information. The CRC is masked with a Radio Network TemporaryIdentifier (RNTI) according to the owner or usage of the PDCCH. If thePDCCH is associated with a specific UE, the CRC may be masked with acell-RNTI (C-RNTI) of the UE. If the PDCCH is associated with a pagingmessage, the CRC may be masked with a paging indicator identifier(P-RNTI). If the PDCCH is associated with system information (morespecifically, a system information block (SIB)), the CRC may be maskedwith a system information identifier and a system information RNTI(SI-RNTI). To indicate a random access response that is a response totransmission of a random access preamble from the UE, the CRC may bemasked with a random access-RNTI (RA-RNTI).

FIG. 4 illustrates the structure of an uplink subframe. The uplinksubframe may be divided into a control region and a data region in thefrequency domain. A Physical Uplink Control Channel (PUCCH) includinguplink control information is allocated to the control region. APhysical Uplink Shared Channel (PUSCH) including user data is allocatedto the data region. In order to maintain single carrier properties, oneUE does not simultaneously transmit the PUCCH and the PUSCH. A PUCCHassociated with one UE is allocated to an RB pair in a subframe. RBsbelonging to the RB pair occupy different subcarriers in two slots. Thatis, the RB pair allocated to the PUCCH is “frequency-hopped” at a slotboundary.

Multi-Antenna System

Multi-antenna technology (i.e., MIMO technology) is an application oftechnology which does not depend on a single antenna path to receive amessage but instead combines data fragments received through multipleantennas to reconstruct the message. The multi-antenna technology isconsidered a next-generation mobile communication technology which canbe widely used for a mobile communication terminal, a relay, and thelike since the technology can improve data transmission rate in aspecific range or can increase a system range for a specific datatransmission rate. The multi-antenna technology has also attractedattention as a next-generation technology which can overcome thelimitation of the transmission capacity of mobile communication that hasreached the limit due to extension of data communication.

The multi-antenna technology can be divided into a spatial multiplexingscheme and a spatial diversity scheme depending on whether or not thesame data is transmitted. The spatial multiplexing scheme is a method ofsimultaneously transmitting different data through multiple transmit andreceive antennas. That is, in the spatial multiplexing scheme, thetransmitting side transmits different data through each transmit antennaand the receiving side identifies transmission data through appropriateinterference removal and signal processing to improve transmission ratein proportion to the number of transmit antennas. The spatial diversityscheme is a method of achieving transmit diversity by transmitting thesame data through multiple transmit antennas. That is, the spatialdiversity scheme is a type of space-time channel coding scheme. Thespatial diversity scheme can maximize transmit diversity gain(performance gain) by transmitting the same data through multipletransmit antennas. The spatial diversity scheme is a technology forincreasing reliability of transmission using diversity gain rather thana method for improving transmission rate. Such two schemes may beappropriately combined to achieve the advantages of the two schemes asappropriate. The multi-antenna system may be classified into an openloop scheme (or a channel independent scheme) and a closed loop scheme(or a channel dependent scheme) according to whether or not thereceiving side feeds channel information back to the transmitting side.

FIG. 5 illustrates a configuration of a general multi-antenna (MIMO)communication system. As shown in FIG. 5( a), if the number of transmitantennas is increased to N_(T) and the number of receive antennas isincreased to N_(R), a channel transmission capacity is theoreticallyincreased in proportion to the number of antennas unlike when aplurality of antennas is used only in a transmitter or a receiver.Accordingly, it is possible to improve transmission rate and toremarkably improve frequency efficiency. As the channel transmissioncapacity is increased, the transmission rate may be theoreticallyincreased by the product of the maximum transmission rate R₀ when asingle antenna is used and a rate increase ratio R_(i) expressed in thefollowing Expression 1

R _(i)=min(N _(T) , N _(R))   Expression 1

For example, in a MIMO system using four transmit antennas and fourreceive antennas, it is possible to theoretically acquire a transmissionrate which is four times that of a single antenna system.

For a more detailed description of a communication method in a MIMOsystem, the communication method may be mathematically modeled asfollows. As shown in FIG. 5( a), let us assume that N_(T) transmitantennas and N_(R) receive antennas are present. The maximum number ofpieces of information that can be transmitted through transmissionsignals is N_(T) when N_(T) transmit antennas are present. Therefore,the transmitted information may be represented by a vector as shown inthe following Expression 2.

s=[s₁, s₂, . . . , s_(N) _(T) ]^(T)   Expression 2

The transmitted information S₁, S₂, . . . , S_(N) _(T) may havedifferent transmission powers. When P₁, P₂, . . . , P_(N) _(T) are thetransmission powers, the transmitted information with adjusted powersmay be represented by a vector as follows.

ŝ=└ŝ₁, ŝ₂, . . . , ŝ_(N) _(T) ┘^(T)=[Ps₁, Ps₂, . . . , Ps_(N) _(T) ]^(T)  Expression 3

In addition, Ŝ may be expressed using a diagonal matrix P of thetransmission powers as shown in the following Expression 4.

$\begin{matrix}{\hat{S} = {{\begin{bmatrix}P_{1} & \; & \; & 0 \\\; & P_{2} & \; & \; \\\; & \; & \ddots & \; \\0 & \; & \; & P_{N_{T}}\end{bmatrix}\begin{bmatrix}s_{1} \\s_{2} \\\vdots \\s_{N_{T}}\end{bmatrix}} = {Ps}}} & {{Expression}\mspace{14mu} 4}\end{matrix}$

Let us consider that the N_(T) actually transmitted signals x₁, x₂, . .. , x_(N) _(T) are configured by applying a weight matrix W to theinformation vector Ŝ with the adjusted transmission powers. Here, theweight matrix W serves to appropriately distribute the transmittedinformation to each antenna according to the state of a transportchannel or the like. x₁, x₂, . . . , x_(N) _(T) may be represented usingthe vector X as shown in the following Expression 5. Here, W_(ij)denotes a weight between an ith transmit antenna and jth information. Wis referred to as a weight matrix or a precoding matrix.

$\begin{matrix}{x = {\quad{\begin{bmatrix}x_{1} \\x_{2} \\\vdots \\x_{i} \\\vdots \\x_{N_{T}}\end{bmatrix} = {{\begin{bmatrix}w_{11} & w_{12} & \ldots & w_{1N_{T}} \\w_{12} & w_{12} & \ldots & w_{2N_{T}} \\\vdots & \; & \ddots & \; \\w_{i\; 2} & w_{i\; 2} & \ldots & w_{{iN}_{T}} \\\vdots & \; & \ddots & \; \\w_{N_{T}1} & w_{N_{T}2} & \ldots & w_{N_{T}N_{T}}\end{bmatrix}\begin{bmatrix}{\hat{s}}_{1} \\{\hat{s}}_{2} \\\vdots \\{\hat{s}}_{i} \\\vdots \\{\hat{s}}_{N_{T}}\end{bmatrix}} = {{W\hat{s}} = {WPs}}}}}} & {{Expression}\mspace{14mu} 5}\end{matrix}$

If N_(R) receive antennas are present, respective received signals y₁,y₂, . . . , y_(N) _(R) of the antennas may be represented by a vector asshown in the following Expression 6.

y=[y₁, y₂, . . . , y_(N) _(R) ]^(T)   Expression 6

If channels are modeled in the MIMO communication system, the channelsmay be distinguished according to transmit and receive antenna indexes.Let h_(ij) represent a channel from the transmit antenna j to thereceive antenna i. Here, note that the indexes of the receive antennasprecede the indexes of the transmit antennas in h_(ij).

Such channels may be represented in combination by a vector or matrix.The following is an example of vector representation. FIG. 5( b)illustrates channels from N_(T) transmit antennas to the receive antennai.

As shown in FIG. 5( b), the channels from the N_(T) transmit antennas tothe receive antenna i may be expressed as follows.

h_(i) ^(T)=[h_(i1), h_(i2), . . . , h_(iN) _(T) ]  Expression 7

When each of the channels from the N_(T) transmit antennas to the N_(R)receive antennas is represented by a matrix as shown in Expression 7,all channels from the N_(T) transmit antennas to the N_(R) receiveantennas may be expressed as in the following Expression 8.

$\begin{matrix}{H = {\begin{bmatrix}h_{1}^{T} \\h_{2}^{T} \\\vdots \\h_{i}^{T} \\\vdots \\h_{N_{R}}^{T}\end{bmatrix} = \begin{bmatrix}h_{11} & h_{12} & \ldots & h_{1N_{T}} \\h_{12} & h_{12} & \ldots & h_{2N_{T}} \\\vdots & \; & \ddots & \; \\h_{i\; 2} & h_{i\; 2} & \ldots & h_{{iN}_{T}} \\\vdots & \; & \ddots & \; \\h_{N_{R}1} & h_{N_{R}2} & \ldots & h_{N_{R}N_{R}}\end{bmatrix}}} & {{Expression}\mspace{14mu} 8}\end{matrix}$

An Additive White Gaussian Noise (AWGN) is added to actual channelsafter the channels undergo such a channel matrix H. The AWGN n₁, n₂, . .. , n_(N) _(R) added to the N_(T) transmit antennas may be expressed asshown in the following Expression 9.

n=[n₁, n₂, . . . , n_(N) _(R) ]^(T)   Expression 9

The received signals obtained using the above Expressions may beexpressed as shown in the following Expression 10.

$\begin{matrix}{y = {\quad{\begin{bmatrix}y_{1} \\y_{2} \\\vdots \\y_{i} \\\vdots \\y_{N_{R}}\end{bmatrix} = {{{\begin{bmatrix}h_{11} & h_{12} & \ldots & h_{1N_{T}} \\h_{12} & h_{12} & \ldots & h_{2N_{T}} \\\vdots & \; & \ddots & \; \\h_{i\; 2} & h_{i\; 2} & \ldots & h_{{iN}_{T}} \\\vdots & \; & \ddots & \; \\h_{N_{R}1} & h_{N_{R}2} & \ldots & h_{N_{R}N_{T}}\end{bmatrix}\begin{bmatrix}x_{1} \\x_{2} \\\vdots \\x_{j} \\\vdots \\x_{N_{T}}\end{bmatrix}} + \begin{bmatrix}n_{1} \\n_{2} \\\vdots \\n_{i} \\\vdots \\n_{N_{R}}\end{bmatrix}} = {{Hx} + n}}}}} & {{Expression}\mspace{14mu} 10}\end{matrix}$

The numbers of rows and columns of the channel matrix H which indicatesthe channel state is determined by the numbers of transmit and receiveantennas. The number of rows of the channel matrix H is equal to thenumber N_(R) of receive antennas and the number of columns thereof isequal to the number N_(T) of transmit antennas. That is, the channelmatrix H may be represented by an N_(R)×N_(T) matrix. Generally, therank of a matrix is defined as the smaller of the number of independentrows and the number of independent columns. Accordingly, the rank of amatrix cannot be greater than the number of rows or columns of thematrix. The rank of the channel matrix H may be expressed as shown inthe following Expression 11.

rank(H)≦min(N _(T) , N _(R))   Expression 11

Uplink Transmission Structure

FIG. 6 is a block diagram illustrating an uplink transmission structure.

An encoding unit of information bits may be referred to as a transportblock (TB). In FIG. 6, a unit input to an encoder corresponds to a TBand an output of the encoder corresponds to a codeword (CW). One or morecodewords may be scrambled using a UE-specific scrambling signal. Eachof the scrambled codewords is modulated into a complex symbol using aBPSK, QPSK, 16 QAM, or 64 QAM scheme according to the type of thetransmission signal and/or the condition of the channel. Thereafter, themodulated complex symbol is mapped to one or more layers.

The TB-to-CW mapping relationship may be defined as follows. Forexample, let us assume that 2 transport blocks are represented by TB1and TB2 and 2 codewords are represented by CW0 and CW1 (or CW1 and CW2).When both transport blocks TB1 and TB2 are enabled, the first transportblock TB1 may be mapped to the first codeword CW0 and the secondtransport block TB2 may be mapped to the second codeword CW1. WhenTB-to-CW swapping is applied, the first transport block TB1 may bemapped to the second codeword CW1 and the second transport block TB2 maybe mapped to the first codeword CW0. When one of the transport blocksTB1 and TB2 is disabled and the other is enabled, the enabled transportblock may be mapped to the first codeword CW0. That is, there is aTB-to-CW mapping relationship in which one transport block is mapped toone codeword. The cases in which a transport block is disabled includethe case in which the size of the transport block is 0. When the size ofa transport block is 0, the transport block is not mapped to a codeword.

The CW-to-layer mapping relationship may be as shown in the followingTables 1 and 2 according to the transmission scheme.

TABLE 1 Number of Number of Codeword-to-layer mapping layers code wordsi = 0, 1, . . . , M_(symb) ^(layer) − 1 1 1 x⁽⁰⁾(i) = d⁽⁰⁾(i) M_(symb)^(layer) = M_(symb) ⁽⁰⁾ 2 2 x⁽⁰⁾(i) = d⁽⁰⁾(i) M_(symb) ^(layer) =M_(symb) ⁽⁰⁾ = x⁽¹⁾(i) = d⁽¹⁾(i) M_(symb) ⁽¹⁾ 2 1 x⁽⁰⁾(i) = d⁽⁰⁾(2i)M_(symb) ^(layer) = M_(symb) ⁽⁰⁾/2 x⁽¹⁾(i) = d⁽⁰⁾(2i + 1) 3 2 x⁽⁰⁾(i) =d⁽⁰⁾(i) M_(symb) ^(layer) = M_(symb) ⁽⁰⁾ = x⁽¹⁾(i) = d⁽¹⁾(2i) M_(symb)⁽¹⁾/2 x⁽²⁾(i) = d⁽¹⁾(2i + 1) 4 2 x⁽⁰⁾(i) = d⁽⁰⁾(2i) M_(symb) ^(layer) =M_(symb) ⁽⁰⁾/2 = x⁽¹⁾(i) = d⁽⁰⁾(2i + 1) M_(symb) ⁽¹⁾/2 x⁽²⁾(i) =d⁽¹⁾(2i) x⁽³⁾(i) = d⁽¹⁾(2i + 1)

TABLE 2 Number Number of Codeword-to-layer mapping of layers code wordsi = 0, 1, . . . , M_(symb) ^(layer) − 1 2 1 x⁽⁰⁾(i) = d⁽⁰⁾(2i) x⁽¹⁾(i) =d⁽⁰⁾(2i + 1) M_(symb) ^(layer) = M_(symb) ⁽⁰⁾/2 4 1 x⁽⁰⁾(i) = d⁽⁰⁾(4i)x⁽¹⁾(i) = d⁽⁰⁾(4i + 1) x⁽²⁾(i) = d⁽⁰⁾(4i + 2) x⁽³⁾(i) = d⁽⁰⁾(4i + 3)$M_{symb}^{layer} = \left\{ \begin{matrix}{M_{symb}^{(0)}/4} & {{{if}\mspace{14mu} M_{symb}^{(0)}{mod}\mspace{14mu} 4} = 0} \\{\left( {M_{symb}^{(0)} + 2} \right)/4} & {{{if}\mspace{14mu} M_{symb}^{(0)}{mod}\mspace{14mu} 4} \neq 0}\end{matrix} \right.$ If M_(symb) ⁽⁰⁾ mod 4 ≠ 0 two null symbols shallbe appended to d⁽⁰⁾(M_(symb) ⁽⁰⁾ − 1)

Table 1 is an example when a signal is transmitted using the spatialmultiplexing scheme and Table 2 is an example when a signal istransmitted using the transmit diversity scheme. In Tables 1 and 2,x^((a))(i) represents an ith symbol and d^((a)(i)) represents an ithsymbol of a codeword having index a. The “Number of layers” and “Numberof codewords” items in Tables 1 and 2 show the mapping relationshipbetween the number of layers and the number of codewords used fortransmission and the “Codeword-to-Layer mapping” items show how symbolsof each codeword are mapped to layers.

Although one codeword may be transmitted by being mapped to one layer ona symbol by symbol basis as can be seen from Tables 1 and 2, onecodeword may also be mapped to up to 4 layers in a distributed manner asin the second case of Table 2. From Table 2, it can be seen that, whenone codeword is distributed and mapped to a plurality of layers in thismanner, symbols of each codeword are transmitted by being sequentiallymapped to the layers. On the other hand, in the case of asingle-codeword based transmission configuration, a single encoder and asingle modulation block are present.

Such a layer-mapped signal may be transform-precoded. Specifically,Discrete Fourier Transform (DFT) precoding may be performed on thelayer-mapped signal. The DFT-precoded signal may be multiplied by aprecoding matrix selected according to the condition of the channel andmay then be allocated to each transmit antenna. Such a processedtransmission signal of each antenna may be mapped to a time-frequencyresource element, which is to be used for transmission, and may then betransmitted through the antenna via an OFDM signal generator.

Uplink Scheduling Information

Control information for scheduling of uplink data transmission may beprovided in the form of a downlink control information (DCI) formatthrough a PDCCH. That is, an uplink transmitting end can acquire controlinformation regarding uplink transmission through a format for uplinktransmission (for example, DCI format 0 or 4) among DCI formats includedin a PDCCH. Control information for uplink transmission may includecontrol information for supporting multiple transport blocks (TBs). Forexample, the control information for uplink transmission may include aModulation and Coding Scheme (MCS), a Redundancy Version (RV), and a NewData Indicator (NDI) and may also include a precoder index. Through aMCS, an RV, an NDV, a precoder index, or the like, it is possible toindicate whether a specific TB is enabled or disabled. The controlinformation for uplink transmission may also include a swap flag forchanging the TB-to-CW mapping. For example, when the basic setting issuch that a first TB is mapped to a first CW and a second TB is mappedto a second CW, enabling a swap flag may set the first TB to be mappedto the second CW and set the second TB to be mapped to the first CW. Insuch a situation in which it is possible to acquire a PDCCH, informationregarding an enabled TB, precoding information, TB-to-CW mapping, andthe like may be determined through DCI format information.

Control Information Transmission in PUSCH

FIG. 7 is a block diagram illustrating a procedure for processing atransport channel for an uplink shared channel (PUSCH). As shown in FIG.7, to transmit data that is to be multiplexed with control information,first, a Cyclic Redundancy Check (CRC) for Transport Block (TB) isattached to a TB for uplink transmission (130) and then the TB isdivided into a plurality of Code Blocks (CBs) according to the size ofthe TB and a CRC for CB is attached to the CBs (131). Channel coding isperformed on the resulting value (132). Channel-coded data items arethen rate-matched (133), the CBs are combined (134), and the combinedCBs are multiplexed with Channel Quality Information/Precoding MatrixIndex (CQI/PMI) (135). In the description of the present invention, theCQI and the PMI may also be collectively referred to as CQI.

The CQI/PMI is channel-coded separately from the data (136). Thechannel-coded CQI/PMI is multiplexed with the data (135). A RankIndication (RI) is also channel-coded separately from the data (137).Acknowledgement/Negative Acknowledgement (ACK/NACK) is channel-codedseparately from the data, the CQI/PMI, and the RI (138). The multiplexeddata and CQI/PMI and the separately channel-coded RI and ACK/NACK arechannel-interleaved to generate an output signal (139).

FIG. 8 illustrates a method for mapping physical resources fortransmitting uplink data and Uplink Control Information (UCI).

As shown in FIG. 8, CQI/PMI and data are mapped to REs in a time-firstmanner. An encoded ACK/NACK is inserted adjacent to DemodulationReference Signal (DM RS) symbols through puncturing and an RI is mappedto REs next to REs at which the ACK/NACK is located. Resources for theRI and the ACK/NACK may occupy up to 4 SC-FDMA symbols. When data andcontrol information are simultaneously transmitted in an uplink sharedchannel, mapping is performed in the order of RI->CQI/PMI and dataconcatenation->ACK/NACK. That is, after the RI is first mapped, theCQI/PMI and data concatenation is mapped in a time-first manner to REsother than REs to which the RI has been mapped. Mapping of the ACK/NACKis performed while puncturing the CQI/PMI and data concatenation whichhas already been mapped.

By multiplexing uplink control information such as data and CQI/PMI inthe above manner, it is possible to satisfy single carriercharacteristics. Thus, it is possible to accomplish uplink transmissionwhich maintains a low Cubic Metric (CM).

The following is a description of a method for multiplexing data and UCIin an uplink shared channel.

A user equipment may identify the rank of data of a physical uplinkshared channel (PUSCH) and set the rank of uplink control information(such as CQI, ACK/NACK, and RI) to the same as the rank of the uplinkdata. The user equipment may multiplex data and control information andmap the data and CQI in a time-first manner and then may map the RI todesignated REs. The user equipment may then perform channel interleavingto facilitate mapping of the ACK/NACK to REs adjacent to the DM-RSthrough puncturing of the REs. Thereafter, the user equipment maymodulate the data and control channel using QPSK, 16QAM, 64QAM, or thelike according to a Modulation and Coding Scheme (MCS) table.

The following is a description of a method for calculating the number ofREs for UCI in a PUSCH. First, the numbers of REs for CQI and ACK/NACK(or RI) transmitted in a PUSCH may be calculated according to thefollowing Expressions 12 and 13.

$\begin{matrix}{Q^{\prime} = {\min \left( {\left\lceil \frac{\left( {O + L} \right) \cdot M_{x}^{{PUSCH}\text{-}{initial}} \cdot N_{symb}^{{PUSCH}\text{-}{initial}} \cdot \beta_{offset}^{PUSCH}}{\sum\limits_{r = 0}^{C^{(x)} - 1}\; K_{r}^{(x)}} \right\rceil,{{M_{sc}^{PUSCH} \cdot N_{symb}^{PUSCH}} - \frac{Q_{RI}}{Q_{m}}}} \right)}} & {{Expression}\mspace{14mu} 12} \\{Q^{\prime} = {\min \left( {\left\lceil \frac{O \cdot M_{x}^{{PUSCH}\text{-}{{initial}{(1)}}} \cdot N_{symb}^{{PUSCH}\text{-}{{initial}{(1)}}} \cdot M_{sc}^{{PUSCH}\text{-}{{initial}{(2)}}} \cdot N_{symb}^{{PUSCH}\text{-}{{initial}{(2)}}} \cdot \beta_{offset}^{PUSCH}}{{\sum\limits_{r = 0}^{C^{(x)} - 1}\; {K_{r}^{(1)} \cdot M_{sc}^{{PUSCH}\text{-}{{initial}{(2)}}} \cdot N_{symb}^{{PUSCH}\text{-}{{initial}{(2)}}}}} + {\sum\limits_{r = 0}^{C^{(x)} - 1}\; {K_{r}^{(2)} \cdot M_{x}^{{PUSCH}\text{-}{{initial}{(1)}}} \cdot N_{symb}^{{PUSCH}\text{-}{{initial}{(1)}}}}}} \right\rceil,{4 \cdot M_{sc}^{PUSCH}}} \right)}} & {{Expression}\mspace{14mu} 13}\end{matrix}$

Here, the numbers of REs for CQI and ACK/NACK (or RI) may each berepresented by the number of coded modulation symbols.

The following is a description of a method for performing channel codingon UCI that is transmitted in a PUSCH. First, when the payload size of aCQI is equal to or less than 11 bits, a Reed-Muller (RM) using thefollowing Table 3 is applied to an input sequence (i.e., informationdata) o₀, o₁, o₂, . . . , o_(o-1) to generate a 32-bit output sequence.In addition, when the payload size of the CQI is greater than bits, tailbiting convolutional coding (TBCC) may be applied to the input sequenceafter an 8-bit CRC is attached to the same.

The following is a description a method for performing channel coding onan ACK/NACK and an RI that are transmitted in a PUSCH. When the datasize of the ACK/NACK and the RI is 1 bit, i.e., when the input sequenceis [o₀ ^(UCI)], channel coding is performed on the ACK/NACK and the RIaccording to a modulation order Qm as shown in the following Table 4.When the data size of the ACK/NACK and the RI is 2 bits, i.e., when theinput sequence is [o₀ ^(UCI) o₁ ^(UCI)], coding is performed on theACK/NACK and the RI according to the modulation order as shown in thefollowing Table 5. In Table 5, o₀ ^(UCI) corresponds to ACK/NACK or RIdata for codeword 0, o₁ ^(UCI) corresponds to ACK/NACK or RI data forcodeword 1, and o₂ ^(UCI) is (o₀ ^(UCI)+o₁ ^(UCI))mod2. In Tables 4 and5, x denotes a value of 1 and y denotes a replication of a previousvalue.

However, if the data size of the ACK/NACK and the RI is equal to orgreater than 3 bits and equal to or less than 11 bits, Reed-Muller (RM)coding using the following Table 3 is applied to the input sequence togenerate a 32-bit output sequence.

TABLE 3 i M_(i, 0) M_(i, 1) M_(i, 2) M_(i, 3) M_(i, 4) M_(i, 5) M_(i, 6)M_(i, 7) M_(i, 8) M_(i, 9) M_(i, 10) 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 0 00 0 0 0 1 1 2 1 0 0 1 0 0 1 0 1 1 1 3 1 0 1 1 0 0 0 0 1 0 1 4 1 1 1 1 00 0 1 0 0 1 5 1 1 0 0 1 0 1 1 1 0 1 6 1 0 1 0 1 0 1 0 1 1 1 7 1 0 0 1 10 0 1 1 0 1 8 1 1 0 1 1 0 0 1 0 1 1 9 1 0 1 1 1 0 1 0 0 1 1 10 1 0 1 0 01 1 1 0 1 1 11 1 1 1 0 0 1 1 0 1 0 1 12 1 0 0 1 0 1 0 1 1 1 1 13 1 1 0 10 1 0 1 0 1 1 14 1 0 0 0 1 1 0 1 0 0 1 15 1 1 0 0 1 1 1 1 0 1 1 16 1 1 10 1 1 1 0 0 1 0 17 1 0 0 1 1 1 0 0 1 0 0 18 1 1 0 1 1 1 1 1 0 0 0 19 1 00 0 0 1 1 0 0 0 0 20 1 0 1 0 0 0 1 0 0 0 1 21 1 1 0 1 0 0 0 0 0 1 1 22 10 0 0 1 0 0 1 1 0 1 23 1 1 1 0 1 0 0 0 1 1 1 24 1 1 1 1 1 0 1 1 1 1 0 251 1 0 0 0 1 1 1 0 0 1 26 1 0 1 1 0 1 0 0 1 1 0 27 1 1 1 1 0 1 0 1 1 1 028 1 0 1 0 1 1 1 0 1 0 0 29 1 0 1 1 1 1 1 1 1 0 0 30 1 1 1 1 1 1 1 1 1 11 31 1 0 0 0 0 0 0 0 0 0 0

TABLE 4 Q_(m) Encoded HARQ-ACK/RI 2 [o₀ ^(UCI) y] 4 [o₀ ^(UCI) y x x] 6[o₀ ^(UCI) y x x x x]

TABLE 5 Q_(m) Encoded HARQ-ACK/RI 2 [o₀ ^(UCI) o₁ ^(UCI) o₂ ^(UCI) o₀^(UCI) o₁ ^(UCI) o₂ ^(UCI) ] 4 [o₀ ^(UCI) o₁ ^(UCI) x x o₂ ^(UCI) o₀^(UCI) x x o₁ ^(UCI) o₂ ^(UCI) x x] 6 [o₀ ^(UCI) o₁ ^(UCI) x x x x o₂^(UCI) o₀ ^(UCI) x x x x o₁ ^(UCI) o₂ ^(UCI) x x x x]

When RM coding using Table 3 is applied, output data b₀, b₁, b₂, b₃, . .. , b_(B-1) is expressed as shown in the following Expression 14 andB=32.

$\begin{matrix}{b_{i} = {\sum\limits_{n = 0}^{O - 1}\; {\left( {o_{n} \cdot M_{i,n}} \right){mod}\mspace{14mu} 2}}} & {{Expression}\mspace{14mu} 14}\end{matrix}$

Finally, rate matching may be performed on the UCI (i.e., ACK/NACK or RIdata), which has been coded into B bits, according to the followingExpression 15 in order to map the UCI to Q′ REs, the number (Q′) ofwhich has been calculated according to Expressions 12 and 13.

q _(i) =b _(i mod B) , i=0, 1, . . . , Q _(m) ×Q′−1   Expression 15

For more details of channel coding of control information in an uplinkshared channel, refer to section 5.2.2.6 of the 3GPP TS 36.212 document.For more details of channel coding of CQI/PMI information in an uplinkshared channel, refer to section 5.2.2.6.4 of the 3GPP TS 36.212document. For more details of multiplexing of data and controlinformation in an uplink shared channel, refer to section 5.2.2.7 of the3GPP TS 36.212 document. In addition, for more details of the channelinterleaver in an uplink shared channel, refer to section 5.2.2.8 of the3GPP TS 36.212 document.

Method for Multiplexing UCI and UL Data in Transmission of MultipleTBs/Multiple CWs/Multiple Layers

An LTE-A system which supports an extended antenna configuration asdescribed above can support uplink transmission of up to 2 TBs (i.e., upto 2 CWs) through up to 4 transport layers. The following is adescription of various embodiments of the present invention in which aTB, a CW, or a layer in which each of the uplink control informationitems (i.e., the CQI, the ACK/NACK, and the RI) is transmitted isdefined when the uplink control information items are multiplexed andtransmitted in uplink data (i.e., a PUSCH).

As described above with reference to FIG. 6 and Tables 1 and 2, in asystem using multiple antennas, a TB is mapped to a CW and a CW ismapped to a transport layer. The following Table 6 shows TB-to-CWmapping CW-to-layer mapping when the number of enables TBs is 1 or 2.

TABLE 6 TB CW Layer A 1st TB 1st CW 1st layer B-1 1st TB 1st CW 1stlayer 2nd TB 2nd CW 2nd layer B-2 1st TB 2nd CW 2nd layer 2nd TB 1st CW1st layer C-1 1st TB 1st CW 1st layer 2nd TB 2nd CW 2nd layer 3rd layerC-2 1st TB 2nd CW 2nd layer 3rd layer 2nd TB 1st CW 1st layer D-1 1st TB1st CW 1st layer 2nd layer 2nd TB 2nd CW 3rd layer

 4 layer D-2 1st TB 2nd CW 3rd layer

 4 layer 2nd TB 1st CW 1st layer 2nd layer E-1 1st TB 1st CW 1st layer2nd layer E-2 1st TB 2nd CW 1st layer 2nd layer

Item A in Table 6 shows that, when the number of enabled TBs is 1 andthe number of transport layers is 1, the 1st TB is mapped to the 1st CWand the 1st CW is mapped to the 1st layer.

Item B in Table 6 shows that, when the number of enabled TBs is 2 andthe number of transport layers is 2, the 1st TB is mapped to the 1st CWand the 2nd TB is mapped to the 2nd CW (B-1) or the 1st TB is mapped tothe 2nd CW and the 2nd TB is mapped to the 1st CW (B-2) and the 1st CWis mapped to the 1st layer and the 2nd CW is mapped to the 2nd layer.

Item C in Table 6 shows that, when the number of enabled TBs is 2 andthe number of transport layers is 3, the 1st TB is mapped to the 1st CWand the 2nd TB is mapped to the 2nd CW (C-1) or the 1st TB is mapped tothe 2nd CW and the 2nd TB is mapped to the 1st CW (C-2) and the 1st CWis mapped to the 1st layer and the 2nd CW is mapped to the 2nd and 3rdlayers.

Item D in Table 6 shows that, when the number of enabled TBs is 2 andthe number of transport layers is 4, the 1st TB is mapped to the 1st CWand the 2nd TB is mapped to the 2nd CW (D-1) or the 1st TB is mapped tothe 2nd CW and the 2nd TB is mapped to the 1st CW (D-2) and the 1st CWis mapped to the 1st and 2nd layers and the 2nd CW is mapped to the 3rdand 4th layers.

Item E in Table 6 shows that, when the number of enabled TBs is 1 andthe number of transport layers is 2, the 1st TB is mapped to the 1st CW(E-1) or the 1st TB is mapped to the 2nd CW (E-2), and the 1st CW ismapped to the 1st and 2nd layers.

As illustrated in Table 6, when data is transmitted through multiplelayers, data and control information may be multiplexed and transmittedin a data channel (PUSCH). Such control information may include CQI, RI,and ACK/NACK information.

First, it is possible to consider that uplink control information (UCI)is multiplexed and transmitted with part of the multiple CWs (forexample, one of the multiple CWs).

Here, although one CW may be mapped to one layer as shown in Table 6,one CW may also be mapped to a plurality of layers. When one CW ismapped to one layer, UCI may be multiplexed in a PUSCH in the samemanner as in the conventional method. On the other hand, when one CW ismapped to multiple layers, UCI may be equally replicated and transmittedin each layer to which the CW is mapped. Replication and transmission ofUCI in each of the layers indicates that each layer includes onecomplete UCI and the same UCI is present in each layer. Alternatively,when one CW is mapped to multiple layers, UCI may be spread andtransmitted in each of the layers to which the CW is mapped. Spreadingand transmission of UCI in a plurality of layers indicates that part ofthe UCI is present in one layer, another part of the UCI is present inanother layer, and the parts are combined to construct one complete UCI.

Next, it is possible to consider that UCI is multiplexed and transmittedwith all multiple CWs (for example, 2 CWs).

In this case, UCI may be equally replicated and transmitted in each ofthe multiple CWs. Alternatively, the UCI may be spread and transmittedin the multiple CWs. Also, in this case, as illustrated in Table 6,layers to which the multiple CWs are mapped are present and UCI may bereplicated and transmitted in a layer to which one CW is mapped or maybe spread and transmitted in the layer.

As described above, replicated/spread transmission of UCI on a CW basisand/or on a layer basis may be applied in various combinations accordingto the attribute of the UCI. For example, CQI information may bemultiplexed and transmitted only with part of the CWs and RI andACK/NACK information may be multiplexed and transmitted with all CWs.Here, the CQI information which is transmitted with part of the CWs maybe replicated and transmitted in all layers to which the part of the CWsis mapped and the RI and ACK/NACK information which is transmitted withall CWs may be replicated and transmitted in all layers to which all CWsare mapped.

The following is a description of a method for selecting a CW with whichUCI is to be multiplexed from multiple CWs when the UCI is multiplexedwith part of the multiple CWs. In the following description, a CW whichis multiplexed with UCI is referred to as a CW which is mapped to UCI.

In the first method, to reduce complexity of selection of a CW to whichUCI is mapped, it is possible to define mapping such that UCI is fixedlymapped to a CW of a specific number (or index) among multiple CWs. Forexample, when UCI is multiplexed and transmitted with uplink data, theUCI may always be mapped to the 1st CW.

In the second method, to increase the probability of success ofreception of UCI by a receiving side, it is possible to define mappingsuch that a CW having a relatively high Signal-to-Interference plusNoise Ratio (SINR) is mapped to UCI. For example, a CW, which isassigned a high MCS level from among MCS levels of CWs (or TBs mapped toCWs) included in downlink control information (DCI) for providingscheduling of uplink data transmission, may be mapped to UCI.

In the third method, UCI may be mapped to a CW which is mapped to alarge number of layers. For example, when 2 CWs are transmitted through3 layers, one of the 2 CWs is mapped to 1 layer and the other CW ismapped to 2 layers. In this case, UCI may be multiplexed and transmittedwith the CW which is mapped to the 2 layers.

In addition to the TB-to-CW mapping relationship and the CW-to-layermapping relationship, each layer may be mapped to one or more antennaports. Referring back to FIG. 6, each layer is input to the precoderafter a CW is mapped to the layer and the precoder then maps each layerto an antenna port. That is, a unit that is input to the encoder isreferred to as a TB, a unit that is input to the scrambling block and isthen input to the mapping block is referred to as a CW, a unit that isinput from the output of the layer mapping block to the precoding blockis referred to as a layer, and the output of the precoding block isreferred to as an antenna port.

The precoding scheme is a method of mapping a layer to an antenna portand the Peak-to-Average Power Ratio (PAPR) or Cubic Metric (CM) of atransmit antenna may be maintained or increased according to theattribute of the precoder that is applied to uplink multi-antennatransmission. It is preferable that, in uplink transmission, a low PAPRbe maintained due to limited transmission power of the user equipment.Accordingly, there is a need to apply a structure capable of maintaininga low PAPR when the precoding scheme is applied. In this regard, it ispossible to maintain a low PAPR when a precoder which maps one layer toeach antenna port is used. For example, when 2 layers are transmittedthrough 2 antenna ports, the 1st layer may be set to be transmittedthrough the 1st antenna port and the 2nd layer may be set to betransmitted through the 2nd antenna port. In addition, when 2 layers aretransmitted through 4 antenna ports, the 1st layer may be set to betransmitted through the 1st and 2nd antenna ports and the 2nd layer maybe set to be transmitted through the 3rd and 4th antenna ports.

Taking into consideration this, it is possible to set aTB-CW-layer-antenna port mapping relationship as shown in the followingTables 7 and 8. Table 7 is associated with the case in which one TB isenabled and Table 8 is associated with the case in which 2 TBs areenabled. In the following description, the 1st TB and the 2nd TB may berepresented respectively by indices, TB1 and TB2, the 1st CW and the 2ndCW may be represented respectively by indices, CW1 and CW2, the 1st to4th layers may be represented respectively by indices, layers 0 to 3,and the 1st to 4th antenna ports may be represented respectively byindices, antenna ports 0 to 4.

TABLE 7 TB CW Layer Antenna Port A-1 1st TB 1st CW 1st layer 1st antennaport 2nd antenna port A-2 2nd TB 1st CW 1st layer 1st antenna port 2ndantenna port B-1 1st TB 1st CW 1st layer 1st antenna port 2nd antennaport 3rd antenna port 4th antenna port B-2 2nd TB 1st CW 1st layer 1stantenna port 2nd antenna port 3rd antenna port 4th antenna port C-1 1stTB 1st CW 1st layer 1st antenna port 2nd antenna port 2nd layer 3rdantenna port 4th antenna port C-2 2nd TB 1st CW 1st layer 1st antennaport 2nd antenna port 2nd layer 3rd antenna port 4th antenna port

A-1 and A-2 in Table 7 show that 1 TB is mapped to 1 CW and is mapped to1 layer and is then transmitted through 2 antenna ports. Although the1st TB may be set by default to be enabled when only one TB is enabledas in A-1, only the 2nd TB may also be enabled as needed as in A-2.

B-1 and B-2 in Table 7 show that 1 TB is mapped to 1 CW and is mapped to1 layer and is then transmitted through 4 antenna ports.

C-1 and C-2 in Table 7 show that 1 TB is mapped to 1 CW and is mapped to2 layers and is then transmitted through 4 antenna ports. In this case,1 layer is mapped to 2 antenna ports.

When only one TB is enabled as in Table 7, UCI may be mapped to theenabled TB. Since the enabled TB is mapped to the 1st CW, mapping of theUCI to the enabled TB has the same effects as mapping of the UCI to the1st CW. Here, when a plurality of layers is mapped to one enabled TB(i.e., CW), UCI may be replicated and transmitted in each layer or maybe spread and transmitted in the layer as described above.

TABLE 8 TB CW layer antenna port A-1 1st TB 1st CW 1st layer 1st antennaport 2nd TB 2nd CW 2nd layer 2nd antenna port A-2 2nd TB 1st CW 1stlayer 1st antenna port 1st TB 2nd CW 2nd layer 2nd antenna port B-1 1stTB 1st CW 1st layer 1st antenna port (0, 0, 0) 2nd antenna port (1, 3,4) 2nd TB 2nd CW 2nd layer 3rd antenna port (2,1,1) 4th antenna port (3,3, 2) B-2 2nd TB 1st CW 1st layer 1st antenna port (0, 0, 0) 2nd antennaport (1, 3, 4) 1st TB 2nd CW 2nd layer 3rd antenna port (2,1,1) 4thantenna port (3, 3, 2) C-1 1st TB 1st CW 1st layer 1st antenna port (0,0, 0, 1, 1, 2) 2nd antenna port (1, 2, 3, 2, 3, 3) 2nd TB 2nd CW 2ndlayer 3rd antenna port (2, 1, 1, 0, 0, 0) 3rd layer 4th antenna port (3,3, 2, 3, 2, 1) C-2 2nd TB 1st CW 1st layer 1st antenna port (0, 0, 0, 1,1, 2) 2nd antenna port (1, 2, 3, 2, 3, 3) 1st TB 2nd CW 2nd layer 3rdantenna port (2, 1, 1, 0, 0, 0) 3rd layer 4th antenna port (3, 3, 2, 3,2, 1) D1 1st TB 1st CW 1st layer 1st antenna port 2nd layer 2nd antennaport 2nd TB 2nd CW 3rd layer 3rd antenna port 4th layer 4th antenna portD-2 2nd TB 1st CW 1st layer 1st antenna port 2nd layer 2nd antenna port1st TB 2nd CW 3rd layer 3rd antenna port 4th layer 4th antenna port

A-1 and A-2 in Table 8 show that 2 enabled TBs are each mapped to 1 CW,1 CW is mapped to 1 layer, and 1 layer is transmitted through 1 antennaport. In this case, 2-antenna-port transmission is performed. B-1 andB-2 in Table 8 show that 2 enabled TBs are each mapped to 1 CW, 1 CW ismapped to 1 layer, and 1 layer is transmitted through 2 antenna ports.In this case, 4-antenna-port transmission is performed.

C-1 and C-2 in Table 8 show that 2 enabled TBs are each mapped to 1 CW,one of the 2 CWs is mapped to 1 layer, the 1 layer is mapped to 2 app,the other CW is mapped to 2 layers, and the 2 layers are each mapped to1 antenna port. In this case, 4-antenna-port transmission is performed.

D-1 and D-2 in Table 8 show that 2 enabled TBs are each mapped to 1 CW,1 CW is mapped to 2 layers, the 2 layers are each mapped to 1 antennaport. In this case, 4-antenna-port transmission is performed.

In the cases of A-1, A-2, D-1, and D-2 of Table 8, the 1st CW is mappedto a specific antenna port. The 1st CW is mapped to the 1st antenna portin the case of 2-antenna-port transmission as in A-1 and A-2 and the 1stCW is mapped to the 1st and 2nd antenna ports in the case of4-antenna-port transmission as in D-1 and D-2. The 2nd CW is also mappedto a specific antenna port. Here, the 2nd CW is mapped to the 2ndantenna port in the case of 2-antenna-port transmission (A-1 and A-2)and the 2nd CW is mapped to the 3rd and 4th antenna ports in the case of4-antenna-port transmission (D-1 and D-2).

On the other hand, in the cases of B-1, B2, C-1, and C-2 of Table 8, the1st CW may be mapped to 2 of the 1st to 4th antenna ports. Here, the 2ndCW may be mapped to the other 2 antenna ports to which the 1st CW is notmapped.

In the case of MIMO transmission in which 2 TBs are enabled, a specificCW is mapped to a specific antenna port. Here, the reliability oftransmission of the specific CW may vary according to the output powerstate of the physical antenna or the characteristics of the poweramplifier of the physical antenna. To increase the probability ofsuccess of signal transmission, there is a need to select a CW, which istransmitted through an antenna port whose channel condition isrelatively good, as a CW with which UCI is multiplexed.

The following is a description of a method for setting UCI to bemultiplexed with a specific TB when one or more TBs are enabled.

First, when one TB is enabled, UCI may be set to be multiplexed with theenabled TB.

Next, when two TBs are enabled, UCI may be set to be multiplexed withone of the two TBs which is always fixed. The fixed TB may always be setto the 1st TB or may always be set to the 2nd TB. When a TB-to-CW swapflag is disabled, the 1st TB may be mapped to the 1st CW and the 2nd TBmay be mapped to the 2nd CW. In this case, UCI may be set to be alwaysmapped to the 1st CW. When the TB-to-CW swap flag is enabled, the 1st TBmay be mapped to the 2nd CW and the 2nd TB may be mapped to the 1st CW.In this case, UCI may be set to be always mapped to the 2nd CW.

Selection of a TB with which UCI is multiplexed may be applieddifferently according to the characteristics of the UCI. For example,CQI may be mapped to a specific TB as described above while RI andACK/NACK information may be set to be mapped to all CWs and all layers.

On the other hand, in some cases, uplink transmission may be performedeven when uplink scheduling information has not been acquired through aPDCCH. For example, when Semi-Persistent Scheduling (SPS) is applied,data may be transmitted/retransmitted for a long time using controlinformation included in a PDCCH which has been received at a specifictime. When data is transmitted without a PDCCH in this manner, UCI mayalso be set to be multiplexed and transmitted with a predeterminedspecific TB in the same manner as described above.

In addition, it is possible to select a TB to which UCI is mappedaccording to the MCS level or the modulation order.

For example, UCI may be set to be multiplexed with a TB which isassigned a high MCS level through a PDCCH and may also be set to bemultiplexed with a TB which is instructed to be assigned a low MCS levelthrough a PDCCH.

Such a TB may also be selected according to the modulation order. Forexample, let us assume that the modulation order and the coding rate arechanged to set an MCS level which enables transmission of the same sizeof TBs. In this case, when the channel quality is low, it may bepossible to perform more robust transmission by applying an MCS levelhaving a low modulation order. Accordingly, when an MCS level whichindicates transmission of the same size of TBs has been set, UCI may beset to be multiplexed with a TB which is assigned an MCS level having alow modulation order among the TBs.

Alternatively, UCI may be set by default to be multiplexed with a TB forwhich a high MCS level has been set and UCI may be set to be multiplexedwith a TB having a low MCS level (low modulation order) when the MCSlevel is a specific MCS level.

UCI may also be set to be mapped only to a TB having a specificmodulation order for more robust transmission of the UCI. For example,UCI may be multiplexed and transmitted only with a TB which is set asQPSK.

FIG. 9 is a flowchart illustrating a method for multiplexing andtransmitting uplink control information and uplink data according to thepresent invention.

An uplink transmission entity (for example, a user equipment) mayacquire 2 TBs (1st and 2nd TBs) in step S910 and may then multiplex theuplink control information (UCI) with only one of the 2 TBs in stepS920. Here, the TB with which the UCI is multiplexed may be determinedto be a TB which is assigned a relatively high MCS level or a TB whichis assigned a relatively low MCS level. Alternatively, the TB with whichthe UCI is multiplexed may be determined to be a TB which has arelatively low modulation order. Such UCI may correspond to at least oneof an RI, a CQI (CQI and/or PMI), and a HARQ ACK/NACK.

In step S930, 1st and 2nd TBs may be encoded to generate 1st and 2nd CWsand, in step S940, the 1st and 2nd CWs may each be mapped to one or morelayers. In step S950, the layers to which the 1st and 2nd CWs are mappedmay each be mapped to one or more antenna ports. In this manner, the UCIand the uplink data may be multiplexed and transmitted through one ormore antenna ports.

Here, the TB-to-CW mapping relationship, the CW-to-layer mappingrelationship, and the layer-to-antenna relationship may follow theexamples of Tables 1, 2, 6 to 8 described above.

In addition, the TB with which the UCI is multiplexed may be mapped toone CW, this CW may be mapped to one or more layers, and the UCI may bereplicated and transmitted or may be spread and transmitted in the oneor more layers.

The features of the various embodiments of the present inventiondescribed above may each be independently applied to the method formultiplexing uplink control information and uplink data according to thepresent invention described above with reference to FIG. 9 or 2 or moreof the embodiments may be simultaneously applied to the method and adescription of the same details as described above is omitted herein forclarity.

In addition, although the uplink transmission entity is exemplifiedmainly by a base station and the uplink transmission entity isexemplified mainly by a user equipment (or terminal) in the abovedescription of the various embodiments of the present invention, thescope of the present invention is not limited thereto. That is, theprinciples of the present invention described above through the variousembodiments of the present invention may be equally applied to the casein which a relay serves as an entity for downlink transmission to a userequipment or serves as an entity for uplink reception from a userequipment or the case in which a relay serves as an entity for uplinktransmission to a base station or serves as an entity for downlinkreception from a base station.

FIG. 10 illustrates a configuration of a transmission device accordingto the present invention.

As shown in FIG. 10, a transmission device 1000 according to the presentinvention may include a reception module 1010, a transmission module1020, a processor 1030, a memory 1040, and a plurality of antennas 1050.The plurality of antennas 1050 indicates that the transmission device1050 supports MIMO transmission and reception. The reception module 1010may receive various signals, data, and information. The transmissionmodule 1020 may transmit various signals, data, and information. Theprocessor 1030 may control overall operation of the transmission device1000.

The transmission device 1000 according to an embodiment of the presentinvention may be configured to multiplex and transmit uplink controlinformation with uplink data. The processor 1030 of the transmissiondevice may be configured to encode 1st and 2nd transport blocks togenerate 1st and 2nd codewords. The uplink control information may bemultiplexed with only one of the 1st and 2nd transport blocks. Theprocessor 1030 may be configured to map each of the 1st and 2ndcodewords to one or more layers. The processor 1030 may be configured toallow the transmission module 1020 to transmit each of the layers towhich the 1st and 2nd codewords are mapped through one or more antennaports.

The processor 1030 of the transmission device 1000 may also function toarithmetically process information such as information received by thetransmission device 1000 and information to be externally transmittedand the memory 1040 may store the arithmetically processed informationor the like for a specific time and may be replaced with a componentsuch as a buffer (not shown).

The features of the various embodiments of the present inventiondescribed above may each be independently applied to the detailedconfiguration of the transmission device 1000 described above or 2 ormore of the embodiments may be simultaneously applied to the detailedconfiguration of the transmission device 1000 and a description of thesame details as described above is omitted herein for clarity.

In addition, the transmission device 1000 may be a user equipment thatreceives a downlink signal from a base station and transmits an uplinksignal to the base station. The description of the transmission device1000 may be equally applied to a relay which serves as a downlinkreception entity or an uplink transmission entity.

The embodiments of the present invention described above may beimplemented by various means. For example, the embodiments of thepresent invention may be implemented by hardware, firmware, software, orany combination thereof.

In the case in which the present invention is implemented by hardware,the methods according to the embodiments of the present invention may beimplemented by one or more Application Specific Integrated Circuits(ASICs), Digital Signal Processors (DSPs), Digital Signal ProcessingDevices (DSPDs), Programmable Logic Devices (PLDs), Field ProgrammableGate Arrays (FPGAs), processors, controllers, microcontrollers,microprocessors, or the like.

In the case in which the present invention is implemented by firmware orsoftware, the methods according to the embodiments of the presentinvention may be implemented in the form of modules, processes,functions, or the like which perform the features or operationsdescribed below. Software code can be stored in a memory unit so as tobe executed by a processor. The memory unit may be located inside oroutside the processor and can communicate data with the processorthrough a variety of known means.

The detailed description of the exemplary embodiments of the presentinvention has been given to enable those skilled in the art to implementand practice the invention. Although the invention has been describedwith reference to the exemplary embodiments, those skilled in the artwill appreciate that various modifications and variations can be made inthe present invention without departing from the spirit or scope of theinvention described in the appended claims. For example, those skilledin the art may combine the structures described in the above embodimentsin a variety of ways. Accordingly, the invention should not be limitedto the specific embodiments described herein, but should be accorded thebroadest scope consistent with the principles and novel featuresdisclosed herein.

Those skilled in the art will appreciate that the present invention maybe embodied in other specific forms than those set forth herein withoutdeparting from the spirit and essential characteristics of the presentinvention. The above description is therefore to be construed in allaspects as illustrative and not restrictive. The scope of the inventionshould be determined by reasonable interpretation of the appended claimsand all changes coming within the equivalency range of the invention areintended to be embraced within the scope of the invention. The inventionshould not be limited to the specific embodiments described herein, butshould be accorded the broadest scope consistent with the principles andnovel features disclosed herein. In addition, it will be apparent thatclaims which are not explicitly dependent on each other can be combinedto provide an embodiment or new claims can be added through amendmentafter this application is filed.

INDUSTRIAL APPLICABILITY

The embodiments of the present invention described above may be appliedto various mobile communication systems.

1. A method for multiplexing and transmitting uplink control informationwith uplink data in a wireless communication system, the methodcomprising: encoding a first transport block and a second transportblock to generate a first codeword and a second codeword; mapping eachof the first and second codewords to at least one layer; andtransmitting each of the at least one layer to which the first andsecond codewords are mapped through at least one antenna port, whereinthe uplink control information is multiplexed with one of the first andsecond transport blocks.
 2. The method according to claim 1, wherein thetransport block with which the uplink control information is multiplexedis a transport block which is assigned a higher MCS level from among thefirst and second transport blocks.
 3. The method according to claim 1,wherein the transport block with which the uplink control information ismultiplexed is a transport block having a lower modulation order fromamong the first and second transport blocks.
 4. The method according toclaim 1, wherein the transport block with which the uplink controlinformation is multiplexed is a transport block which is modulatedaccording to a Quadrature Phase Shift Keying (QPSK) scheme from amongthe first and second transport blocks.
 5. The method according to claim1, wherein the uplink control information is replicated in at least onelayer to which a codeword to which the transport block with which theuplink control information is multiplexed is mapped is mapped.
 6. Themethod according to claim 1, wherein the uplink control information isspread in at least one layer to which a codeword to which the transportblock with which the uplink control information is multiplexed is mappedis mapped.
 7. The method according to claim 1, wherein the uplinkcontrol information includes at least one of rank information, channelquality information, and Hybrid Automatic Repeat reQuest(HARQ)-Acknowledgement/Negative Acknowledgement (ACK/NACK) information.8. A transmitter for multiplexing and transmitting uplink controlinformation with uplink data in a wireless communication system, thetransmitter comprising: a transmission module for transmitting an uplinksignal to an uplink receiver; a reception module for receiving adownlink signal from the uplink receiver; and a processor forcontrolling the transmitter including the reception module and thetransmission module, the processor being configured for encoding a firsttransport block and a second transport block to generate a firstcodeword and a second codeword, mapping each of the first and secondcodewords to at least one layer, and transmitting, using thetransmission module, each of the at least one layer to which the firstand second codewords are mapped through at least one antenna port,wherein the uplink control information is multiplexed with one of thefirst and second transport blocks.
 9. The transmitter according to claim8, wherein the transport block with which the uplink control informationis multiplexed is a transport block which is assigned a higher MCS levelfrom among the first and second transport blocks.
 10. The transmitteraccording to claim 8, wherein the transport block with which the uplinkcontrol information is multiplexed is a transport block having a lowermodulation order from among the first and second transport blocks. 11.The transmitter according to claim 8, wherein the transport block withwhich the uplink control information is multiplexed is a transport blockwhich is modulated according to a Quadrature Phase Shift Keying (QPSK)scheme from among the first and second transport blocks.
 12. Thetransmitter according to claim 8, wherein the uplink control informationis replicated in at least one layer to which a codeword to which thetransport block with which the uplink control information is multiplexedis mapped is mapped.
 13. The transmitter according to claim 8, whereinthe uplink control information is spread in at least one layer to whicha codeword to which the transport block with which the uplink controlinformation is multiplexed is mapped is mapped.
 14. The transmitteraccording to claim 8, wherein the uplink control information includes atleast one of rank information, channel quality information, and HybridAutomatic Repeat reQuest (HARQ)-Acknowledgement/Negative Acknowledgement(ACK/NACK) information.